Compute shader occlusion test only works with scene camera

Question

Using Unity 2022.3.40f1 and URP.

I'm trying to implement occlusion culling with the depth buffer in a compute shader.

I don't know what's wrong here but my code only works fine with the scene camera but not the game camera.
I have already debugged the depth texture and it works fine.

Any ideas what's missing here?

My shader setup looks like this:

void Render (uint3 id : SV_DispatchThreadID)
{
 
    Chunk chunk = chunkBuffer[id.x];
 
    float4 clipPos = UnityWorldToClipPos(chunk.position);
    float2 screenPos = ComputeScreenPos(clipPos);
    
    float4 projectedPos = mul(UNITY_MATRIX_VP, float4(chunk.position, 1.0f));
    float2 projectedUV = (projectedPos.xy / projectedPos.w + 1.0f) * 0.5f; 
    
    float sceneDepth = _DepthTexture.SampleLevel(sampler_DepthTexture, projectedUV, 0).r;
    
    float chunkDepth = (projectedPos.z / projectedPos.w);
    if (chunkDepth < sceneDepth) {
      return; //  is occluded
    }
}

Answer 1

The issue was UNITY_MATRIX_VP. I had to calculate my own view projection matrix like this: GL.GetGPUProjectionMatrix(_cam.projectionMatrix, false) * _cam.worldToCameraMatrix;